CVE-2021-23771Network attack vector

Sandbox escape via unrestricted main-context access

Published Mar 17, 2022 · Updated Sep 17, 2024

Sandbox escape in notevil 1.3.3 and earlier and argencoders-notevil 2.5.0 and earlier allows remote attackers to modify object prototypes. The evaluator fails to restrict evaluated code from reaching the main JavaScript context, where crafted expressions can add or change prototype properties. The consuming application must pass attacker-controlled code into the evaluator; successful exploitation breaches the intended sandbox and can corrupt objects in the host process.

CVSS severity6.5
Medium
EPSS probability1.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sandbox escape in notevil 1.3.3 and earlier and argencoders-notevil 2.5.0 and earlier allows remote attackers to modify object prototypes. The evaluator fails to restrict evaluated code from reaching the main JavaScript context, where crafted expressions can add or change prototype properties. The consuming application must pass attacker-controlled code into the evaluator; successful exploitation breaches the intended sandbox and can corrupt objects in the host process.

The record

CVE
CVE-2021-23771
Published
Mar 17, 2022
Updated
Sep 17, 2024
Vendor
Argencoders-notevil Project
Product
argencoders-notevil
Classifications
CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 17, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Argencoders-notevil Project · argencoders-notevilversion=0 <unspecified
Matt McKegg · notevilversion=0 <unspecified

Published CVSS scores

6.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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